Mercury is a metal poison which occurs in its elemental form, inorganically as salts, or organically as organomercury compounds. Mercury damages the central nervous system, endocrine system, kidneys, and other organs, and adversely affects the mouth, gums, and teeth. Exposure over long periods of time or heavy exposure to mercury vapor can result in brain damage and ultimately death.

Mercury is a highly toxic substance that can cause chronic or acute poisoning. Some symptoms of excessive mercury exposure include tremors, chest pain, dyspnea, cough, and hemotypsis among other things.

Mercury is toxic, meaning that it can cause both damage and death. It is the only metal that is a liquid at room temperature. When in liquid form it is slightly toxic. When vapor it is highly toxic and can cause brain and liver damage. Some mercury compounds will cause death if only a couple drops tough the skin. The difference in damage and death lies in how it is absorbed.